Wireless networks are gaining popularity because wireless infrastructures are typically easier and less expensive to deploy than wired networks. However, wireless networks can be susceptible to environmental conditions, interference and self-interference.
Access points of wireless networks can provide client devices with wireless access to the networks. For example, FIG. 1 shows a wireless network that includes access points 120, 122, 124. The access points 120, 122, 124 are typically wire connected to a wired network 110 that is connected to the internet 100.
Typically, wireless access points (such as access points 120, 122, 124) transmit MAC (media access control) addresses, such as, BSSID (base service set identification) beacons (1A-1N, 2A-2N, 3A-3N) that provide a client device with information, for example, regarding networks that the wireless access points support. Based upon the received BSSID beacons, the client device can select which access points, and therefore, which networks to associate with. The transmission of the BSSID beacons, however, occupies valuable transmission air-time. That is, the transmission of the BSSID beacons occupies transmission air-time that can reduce the usability of the air-time to other types of wireless communications.
FIG. 2 shows a time-line and depicts BSSID beacons being randomly transmitted from multiple access nodes. The spacing of the BSSIDs can be such that they reduce the usable air-time space available for other wireless network transmissions. That is, for example, medium access protocols such as 802.11 implement Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). In such protocols, transceivers sense a channel (link) and defer transmissions while the channel is considered to be busy. The channel is deemed to be busy if a received signal exceeds a Clear Channel Assessment Threshold (CCAT). Once the CCAT has been tripped, the 802.11 devices can no longer transmit any signals. Therefore, an 802.11 device in the presence of many randomly transmitted beacons can be limited to transmitted data in a very limited amount of air-time.
For a wireless network that includes a high density of access points (access nodes), such as a wireless mesh network, the air-time occupied by the BSSID beacons transmitted by the access nodes can become undesirably large, and effectively reduce the usable air-time of the wireless network.
It is desirable for a wireless network to transmit multiple BSSID beacons without prohibitively reducing the usable airtime available to devices of the wireless network.